A hundred years ago, buildings were kept cool with awnings and shading devices; In the Middle East, they often used mashrabiya, or architectural screens. It made sense to stop the sun and its heat before it got into the building. Then cheap air conditioning made it economical just to pump the heat out and shading went out of fashion. Now, nice shades are back; they not only beat the heat, but they can add a lot of visual interest to a building. In Abu Dhabi, architecture giant Aedas designed the Al Bahar towers with giant computer controlled triangular facets that shade the building when required and open up when not. Architect Chris Wilkinson, a juror for the Tall Building Innovation Awards, described it:

The dynamic façade on Al Bahar, computer-controlled to respond to optimal solar and light conditions, has never been achieved on this scale before. In addition, the expression of this outer skin seems to firmly root the building in its cultural context.

Springwise notes that it cuts the air conditioning requirement way down.

And whereas most buildings in the region feature heavily tinted windows — relying largely on artificial interior lighting instead — Al Bahar Towers was able to reduce that necessity considerably, allowing a much better level of natural light inside. Photovoltaic cells on the south-facing roofs of each tower, meanwhile, generate roughly five percent of the buildings’ total required energy.

It is a complicated system with a lot of moving parts; I wonder what will happen in a few years if it gets gummed up with sand. However that traditional arabic design idea of a screen that keeps out the sun still works.